Generally, known automatic fire protection sprinklers include a sprinkler frame or body with an inlet that that is connected to a supply of firefighting fluid under pressure. Disposed within the outlet of sprinkler body is a sealing element to prevent the discharge of fluid from the outlet. The sealing element is held in place by a thermally responsive trigger. The trigger is supported directly or indirectly against the sprinkler frame in order to maintain the sealing element within the outlet. Accordingly, in an unactuated state of the sprinkler, the sealing element and trigger are subject to a static load from the fluid pressure.
In response to a sufficiently sized fire or other heat source, the thermally responsive trigger actuates thereby releasing the sealing element to permit discharge of fluid from the sprinkler outlet. The discharged fluid impacts a deflector member disposed at a distance from the outlet for distribution of the fluid. The deflector member can either be disposed in a fixed distance relationship with respect to the sprinkler outlet, i.e., a fixed deflector or alternatively, the deflector can translate with respect to the sprinkler outlet.
U.S. Pat. No. 5,664,630 shows and describes exemplary embodiments of fixed deflector sprinkler assemblies. FIG. 1 of U.S. Pat. No. 5,664,630 shows a one piece frame arm(s) and body sprinkler frame with a knuckle or apex formed at the end of the frame arms. Centrally affixed about the knuckle is a deflector. The deflector includes a central bore that is disposed over an end of the knuckle and secured by swaging. Disposed within the outlet of the sprinkler frame is a plug which is supported by a thermally responsive bulb. The bulb is retained between the plug and the knuckle by a compression screw threaded through the knuckle and acting on the bulb.
These known sprinkler assemblies can present some design limitations and manufacturing complexities. For example, the fixed deflector assembly with the one piece frame, arms and knuckle defines only a single fixed distance between the deflector and the sprinkler outlet. Moreover, each of the fixed and translating deflector assemblies can involve manufacturing and assembly of multiple interconnected components including a compression screw separate from the sprinkler frame, surrounding structure and/or deflector member. It may be desirable to provide sprinkler assemblies that overcome some of these design limitation while presenting a more simplified construction.